arXiv research

In this paper we study the problem of existence of orbifold Kaehler-Einstein metrics on del Pezzo surfaces of degree 1 with Du Val singular points. Moreover we compute global log canonical thresholds of del Pezzo surfaces of degree 1 with Du Val singularities and of del Pezzo surfaces of Picard rank 1 with Du Val singu…

Smooth resolutions found for quotient of R^2 by infinite discrete groups.

Study symplectic cohomology of certain singularities using homological mirror symmetry.

Study on homology groups of cDV singularity links, identifying their topology.

The paper extends deformation theory to Calabi-Yau varieties with isolated log canonical singularities.

Extends results on smoothability of singular Fano and Calabi-Yau varieties.

Let W -> X be a real smooth projective 3-fold fibred by rational curves. J. Kollár proved that, if W(R) is orientable, then a connected component N of W(R) is essentially either a Seifert fibred manifold or a connected sum of lens spaces. Our Main Theorem, answering in the affirmative three questions of Kollár, gives s…

In this paper we study the parabolic evolution equation $\partial_t u=(|Du|^{2}+2|\det Du|)^{-1} Δu$, where $u : M\times[0,\infty) \to N$ is an evolving map between compact flat surfaces. We use a tensor maximum principle for the induced metric to establish two-sided bounds on the singular values of Du, which shows tha…

Study symplectic 4-orbifolds with vanishing canonical class, finding new structures and resolutions.

S. Alesker has shown that if $G$ is a compact subgroup of O(n) acting transitively on the unit sphere $S^{n-1}$ then the vector space $Val^G$ of continuous, translation-invariant, $G$-invariant convex valuations on $R^n$ has the structure of a finite dimensional graded algebra over $R$ satisfying Poincare duality. We s…

Meta-learning performance depends on train-validation split type.

Motivated by the importance and universal character of phase singularities which are clarified recently, we study the local structure of equi-phase loci near the dislocation locus of complex valued planar and spatial waves, from the viewpoint of singularity theory of differentiable mappings, initiated by H. Whitney and…

Study empty polar varieties' impact on singular function-germs.

Du, Kakade, Wang, and Yang recently established intriguing lower bounds on sample complexity, which suggest that reinforcement learning with a misspecified representation is intractable. Another line of work, which centers around a statistic called the eluder dimension, establishes tractability of problems similar to t…

We study the asymptotics as $p\uparrow 2$ of stationary $p$-harmonic maps $u_p\in W^{1,p}(M,S^1)$ from a compact manifold $M^n$ to $S^1$, satisfying the natural energy growth condition $\int_M|du_p|^p=O(\frac{1}{2-p}).$ Along a subsequence $p_j\to 2$, we show that the singular sets $Sing(u_{p_j})$ converge to the sup…

Classifies singularities in quiver varieties for specific Dynkin quivers.

Unique tangent cones found for Kahler-Einstein metrics on singular varieties.

The paper proves the existence of singular cscK metrics on smoothable varieties.

In this paper we study nonparametric mean curvature type flows in $M\times\mathbb{R}$ which are represented as graphs $(x,u(x,t))$ over a domain in a Riemannian manifold $M$ with prescribed contact angle. The speed of $u$ is the mean curvature speed minus an admissible function $ψ(x,u,Du)$. Long time existence and unif…

Study Kähler-Einstein metrics on singular varieties, proving metric completion properties.

Proves orbifold singularities for Ricci-flat metrics on certain Kähler varieties.

Compact RCD spaces derived from singular Kahler metrics on 3D projective varieties.

Study two types of singular Kähler-Einstein metrics on complex varieties.

Study on weighted cscK metrics on Kähler varieties with singularities.

Proof of complex geometry theorem for specific singular spaces.

The paper examines solutions to a specific type of nonlinear equation in a disk, proving existence and uniqueness.

Indices of vector fields and 1-forms studied for singular varieties and actions.

Solves local minima problems on smooth manifolds.

The Poincaré-Hopf theorem is extended to projective varieties with isolated singularities.

We determine explicitly the foliated cohomology $H_{\cal F}^\ast (M)$ of the affine Reeb flow ${\cal F}$ on the Hopf manifold ${\Bbb S}^n\times {\Bbb S}^1$. The vector space $H_{\cal F}^1(M)$ contains exactly the obstructions to solve the cohomological equation $X\cdot f=g$ where $f$ and $g$ are $C^\infty$-functions a…

Uniformizes varieties with log-canonical singularities using ball quotients.

The Poincaré-Hopf theorem is extended to projective varieties with isolated singularities.

We prove the Yau-Tian-Donaldson's conjecture for any $\mathbb{Q}$-Fano variety that has a log smooth resolution of singularities such that the discrepancies of all exceptional divisors are non-positive. In other words, if such a Fano variety is K-polystable, then it admits a Kähler-Einstein metric. This extends the pre…

It is given the diffeomorphism classification on generic singularities of tangent varieties to curves with arbitrary codimension in a projective space. The generic classifications are performed in terms of certain geometric structures and differential systems on flag manifolds, via several techniques in differentiable …

Gradient flow method solves isoperimetric inequality for maps.

The paper studies how the singularity of character varieties changes when representations are extended.

In this note we discuss the problem of resolving conically singular cscK varieties to construct smooth cscK manifolds, showing a glueing result for (some) crepant resolutions of cscK varieties with discrete automorphism groups.

Generalizes Toledo invariant to singular klt varieties, proving Milnor-Wood inequality.

The dimensions of the spaces of $k$-homogeneous $\mathrm{Spin}(9)$-invariant valuations on the octonionic plane are computed using results from the theory of differential forms on contact manifolds as well as octonionic geometry and representation theory. Moreover, a valuation on Riemannian manifolds of particular inte…

In this paper, we prove that any two birational projective varieties with finite quotient singularities can be realized as two geometric GIT quotients of a non-singular projective variety by a reductive algebraic group. Then, by applying the theory of Variation of Geometric Invariant Theory Quotients ([3]), we show tha…

Study of symplectic manifolds degenerating into singular spaces.

Study projective KLT varieties with projectively flat cotangent sheaves.

We introduce Graph-Sparse Logistic Regression, a new algorithm for classification for the case in which the support should be sparse but connected on a graph. We val- idate this algorithm against synthetic data and benchmark it against L1-regularized Logistic Regression. We then explore our technique in the bioinformat…

Describes spectral data for singular fibres of a specific Hitchin system.

Paper generalizes Schwarz Lemma for VT harmonic maps with conditions.

The Miyaoka-Yau inequality is proven for certain singular varieties with big canonical or anticanonical divisors.

For a G-invariant holomorphic 1-form with an isolated singular point on a germ of a complex-analytic G-variety with an isolated singular point (G is a finite group) one has notions of the equivariant homological index and of the (reduced) equivariant radial index as elements of the ring of complex representations of th…

Proves certain Calabi-Yau varieties are projective.